The present invention relates to holder for a high-voltage lamp. More particularly this invention concerns halogen lampholder.
A standard lampholder, for instance for a high-voltage metal-halide lamp, has a ceramic or porcelain socket having an inner end and forming an outwardly open hole defining an axis and adapted to fit with a base of a high-voltage lamp, a base fittable against the inner end, and a U-shaped clip holding the socket to the base.
With halogen lamps with a standard G12 base use a socket normally about 36 mm in diameter. Contacts seated in the base fit with pins on the lamp and are connected to lead wires or have terminal screws so standard line current or more can be fed to the lamp fitted in the hole in the socket part. The base is a ceramic disk. The clip is U-shaped and has a bight that engages over the disk and a pair of arms that engage up in the socket, with tabs on the arm bearing on the socket to prevent inward movement. The lamp itself is gripped between the outer ends of the arms so that it does not fall out of the socket.
It is normally considered necessary that the parts be made of ceramic or porcelain to withstand the considerable heat of, for instance, a high-voltage halogen lamp. These materials are hard to form accurately, so that it is difficult to make the described lampholder to the tolerances necessary for easy mass manufacture.
A lampholder has according to the invention a socket having an inner end, formed with seats adapted to hold contacts, and forming an outwardly open hole defining an axis and adapted to fit with a base of a high-voltage lamp and a base fittable against the inner end and having a floor formed with an axially throughgoing hole. A clip is formed with a bight engaged in the hole, a pair of arms extending from respective ends of the bight axially outward into the socket, outer tabs on the arms bearing axially inward on the socket, and inner tabs at the bight bearing axially outward on the floor of the base so that the clip holds the socket and base together.
Thus it is possible to premount the contacts in the base and then simply clip the base to the socket. Once the base is fitted with the contacts, it is a simple task to assemble the lampholder. The bight of the clip itself closes the hole in the base.
According to the invention the floor has an inner face turned away from the socket and formed adjacent the hole with recessed seats holding the inner tabs so that the clip does not project past the floor inner face. In addition the inner tabs are punched out of the arms. They are elastically deformable and press the socket axially outward against the outer tabs. Thus the entire lampholder can be assembled without the use of tools, just snapped together.
In accordance with a further feature of this invention the socket and base have axially interfitting and complementary formations. The base is molded plastic, for instance polyphenyl sulfide or liquid crystal polymer, so that it can be molded to an exact shape. The socket is porcelain or ceramic.